Texas ILINet Structure and Operation th Annual Texas Public Health Association Conference April 21-23, 2010 South Padre Island, Texas Gary Heseltine MD MPH Infectious Disease Control Unit Chronic Illnesses Demand Chronic Attention
Overview What is ILINet What is the structure of ILINet – Where does the data come from – Who is represented How does ILINet operate – Data handling – Stability of operation Possible Improvements to ILINet
Influenza Like Illness (ILI) Net CDC hosted syndromic reporting system – Fever > 100 o F and cough or sore throat Clinicians report weekly – Total number patient visits – Total number of patients diagnosed with ILI Cases divided into 4 age strata Statewide weekly ILI index – Combine data from all clinicians ILI index = total ILI patients/total patient visits
Texas ILI Index: What Does It Mean?
ILINet Evolution YearReportersILI PatientsTotal VisitsCountiesReport/County ,23779, ,232184, ,244517, ,020696, ,6071,018, ,9631,018, ,3351,041, Total 167,6384,558,848
Reporters
Total Number of Weekly Submissions by Reporter
Weighting
8
Tuning Surveillance Levels Weight county Weight block Data View county Data View block
ILINet Data: Two Issues 1.ILINet data reported to the state does not reflect county populations – Weight county contributions to reflect underlying population proportion – Use sampling index to guide resource allocation and recruiting for ILINet to obtain proportionality 2. Sampling method itself: non-probability – Clinicians (reporters) are volunteers- bias – Convenience sample - bias – Use a probability sample to correct for ILINet sampling bias before submission to the state